High pressure sealing means

ABSTRACT

A sealing means for providing a fluid tight joint between assembled components of valves adapted for high temperature-high pressure service. The sealing means is comprised of a metallic ring, V-shaped in radial cross section through its annulus and engaged at its outer apex by a similarly shaped recessed surface of an annular rigid follower. Forcing the follower axially against the ring spreadingly deforms the ring in a radial direction into a firm sealing engagement against opposing walls of adjacent components.

[72] lnventor:

United States Patent Ferrill HIGH PRESSURE SEALING MEANS Homer E.Ferrill, Alexandria, La.

[73] Assignee: Dresser Industries, Inc., Dallas,

Tex.

[22] Filed: May 18, 1970 [21] Appl. No.2 38,425

{52] US. Cl. ..277/l02, 277/205, 277/235,

[51] Int. Cl. ..Fl6j 15/08 [58] Field of Search ..277/102-l06, 112,277/113, 114, 117-121, 205, 235 A, 235;

[56] References Cited UNITED STATES PATENTS 6/1953 Bertrand.,.......277/235 A 7/1962 Burrows ..277/205 11/1941 Dunlevy ..277/205 X 51Sept. 12, 1972 FOREIGN PATENTS OR APPLICATIONS 985,295 3/1951 France..277/205 Primary Examiner-William F. ODea Assistant Examiner-Robert L.Smith Attorney-Robert W. Mayer, Thomas P. Hubbard, Jr., Daniel Rubin,Raymond T. Majesko, Roy L. Van Winkle, William E. Johnson, Jr. and[Eddie E. Scott [57] ABSTRACT A sealing means for providing a fluidtight joint between assembledcomponents of valves adapted for hightemperature-high pressure service. The sealing means is comprised of ametallic ring, V-shaped in radial cross section through its annulus andengaged at its outer apex by a similarly shaped recessed surface of anannular rigid follower. Forcing the follower axially against the ringspreadingly deforms the ring in a radia1 direction into a firm sealingengagement against opposing walls of adjacent components.

10 Claims, 6 Drawing Figures Patented Sept. 12,,1972 v 3,690,682

3 Sheets-Sheet 1 FIG. 2

INVENTOR HOMER E. FERRILL ATTORNEY Patented Sept. 12, 1972 3,690,682

3 Sheets-Sheet 2 FIG.3

64 40 FIG. 4 63 lNVENTOR 23 HOMER E. FERRILL ATTORNEY Q WQJM.

1 HIGH PRESSURESEALING MEANS BACKGROUND or TI-IE'INVENTION The fieldofart to which the invention pertains includes the art of joint packingfor valves.

Construction of valves suitable for high temperaturehigh pressureservice frequently require one or more seals for maintaining assembledjoints pressuretight. Since any escaping fluid could present a serioushazard to local personnel, not to mention the adverse affect on.

the system of which it is a part, the seal and its ability to maintain apressure tight joint represents a highly significant componentinensuring serviceability of the valve. For these reasons, gaskets or thelike of generally resilient materials are regarded as unsuitable forthis type service. At the same time, many joints which such forhightemperature-high pressure likewise require adequate seals to ensureagainst leakage but because of more accessible and/or readily insertableseal location as in the coupling or flange, the problems associatedtherewith are not nearly as acute as in a valve assembly of a typereferred to above. A seal for pipeline service is disclosed inU.S. Pat.No. 1,965,273.

' SUMMARY OF THE INVENTION This invention relates to sealingmeans formaintaining a fluid tight joint between assembled components of valvesparticularly adapted for high temperature-high pressure service. Morespecifically, the invention relates to certain specific improvements insealing means providing a fluidtight se'al at a joint such as formedbetween a hollow valve body, and an element such as a valve bonnet orbushing having a tubular portion passed through an opening therefor inthe body and received telescopically threaded therein.

In accordance herewith a joint seal at the aforementioned location isformed by a thin walled, metallic seal ring substantially -V-shaped inradial section as to form two spaced circumferential legs. The ring isfirst placed spanning the joint to be maintained with its legs overlyingand facing concentric and adjacent annular shouldered channels orgrooves in contiguous components between which the joint is located. Forreasons as will be explained, the inner and outer legs are inclinedradially inwardly and outwardly, respectively, at an angle ofapproximately relative to a planeextending transversely of the ringaxis. A follower ring, of more rigid mass than the seal ring, conformsand fits between opposing circumferential walls of the adjacentchannels. The under axial surface of the follower ring is annularlygrooved to engage against the apex of the seal ring. Application of anaxially inward force against the fo lower ring, as by bolting anoverflange or collar, causes the seal ring to spread radially diverginguntil firm uniform engagement against the opposite channel walls isachieved.

With the abovearrangement the former expense associated with carefulassembly and special machining for prior art seals is dispensed with.Instead, only ordinary assembly care and ordinary machining is requiredtherebysubstantially reducing costs attributed to this aspect ofmanufacture. Since assembly is less difficult than with prior seals,sealing is assured despite reassembly by less skilled field servicepersonnel at customer locations. I

It is therefore an object of the invention to provide an improved sealconstruction for high pressure-high temperature valves. 1

It is a further object of the invention to provide an improved seal asin the :aforesaid'object suitable for maintaining pressure tight jointsinternally located between coaxially assembled valve components.

It is a still further object of the invention to provide a seal as inthe lastmentioned object and which is substantially less costly tomanufacture than are similar purpose seals of the prior art.

BRIEF DESCRIPTION OF TH DRAWINGS FIG. 1 is a vertical'section through aglobe valve of generally conventional type on the plane of theaxis ofthe'valve stem and illustrating the employment of a seal, according tothe present invention, for sealing the joint between the valve body andbonnet;-

FIG. 2 is a fragmentary view of an enlarged scale showing a portion ofthe apparatus as illustrated in FIG. i

FIG. 3 is a vertical section similar to FIG. 1 through a safety reliefvalve of a commercially available type and illustrating the employmentof a seal, according to the present invention, for sealingthe jointbetween the valve base and telescopically received bushing;

FIG. 4 is a viewon an enlarged scale showing a portion of the apparatusillustrated in FIG. 3; and

FIGS. Sand 6 are-views on a still further enlarged scale than FIGS. 2and 4 showing the sealing ring for eitherabove valve type in its normal,relaxed position and in its compressed position, respectively.

Referring to FIGS. 1 and 2 of the drawings, the numeral l0 designatesgenerally a globe valve of a type disclosed in aforementioned US. Pat,No. 3,046,026. T he valve includes a body 11, having a rising stem 12,secured in place by means of a valve bonnet 13. The bonnet terminates atits lower end via a tubular portion 14 telescopically received in bore15 whereat it is threaded to body 11. An annular radially enlargedflange 16 connects valve bonnet 13 to body 11 by means of bolts 17.

Referring now to FIGS. 3 and 4, the numeral 22 designates generally apressure relief valve of a type more fully disclosed in U.S. Pat. No.3,354,896. The valve includes a body or base 23 in which a bushing 24has a tubular end portion 25 telescopically received in a bore 26thereof. The bushing is secured by threads 27 to the body and has avalve seat 28 on its inner end. An annular radially enlarged flange 32,which corresponds to the flange 16 of FIGS. 1 and 2, is connected bybolts 33 to the body 23. In this instance flange 32 comprises one end ofa discharge collar 34 surrounding the outer end 35 of the bushing 24. Anopposite flange 36 is adapted for connecting the valve to a dischargefluid conduit (not shown). This arrangement permits the bushing to beremoved from body 23 for inspection and/or servicing of valve seat 28.

As can be best seen in FIGS. and 6, there is shown the inventionsubstantially as illustrated in FIGS. 1-4, and for the sake ofexplanation will be described in reference to the valve structure ofFIGS. 3 and 4. In this instance, the joint to be sealed is representedby an axially extending annular opening 40 formed between juxtaposedwalls 41 and 42 of contiguously assembled body 23 and bushing 24.Despite a close surface fit between these components the joint 40 isrelatively in unsealed communication with pressurized fluid contained inbore chamber 26.

At the egress end of opening 40, body 23 and bush ing 24 radiallydiverge in a coplanar relation to form annular right angleperipheralchannels or grooves 43 and 44 including circumferential wall surfaces 45and 46 respectively. Flange 32 likewise has a right angle annularchannel or groove 50 at the juncture of its inner periphery with itsinner face and including circumferential wall surface 51axially-coextensive with wall inclined radially inwardly and outwardlyat an angle a of substantially relative to a plane extendingtransversely of the ring axis. Contained within channel 50 is a followerring 60 conforming generally to the bottom and sides thereof andincluding an annular or circumferentially grooved recess 61 on itsunderside. The recess 61 is V-shaped in section of less shallowinclination than that of ring 52 and acts asa die forming member whenurged against apex 56 of the latter.

To form the seal, flange 32 is forced axially inward of the valve bytightening bolts 33 until the gap 62 shown in FIG. 5, disappears as theflange face 63 engages against the mating body surface 64 in the mannerof FIG. 6. In so doing follower ring 60 is moved axially inward and actsto compress the sealing ring 52 causing it to spread radially inward atleg 54 and outward at leg 55. The spreading of ring 52 continues untilbolts 33 are adequately torqued and. the change which occurs withrespect to ring 52 can be best appreciated by careful comparison ofFIGS. 5 and 6. On achieving the relation of FIG. 6, the seal iscompleted with ring 52 in firm, uniform circumferential engagementagainst side walls 45 and 46. On disassembly for servicing or thelike,'ring S2 reverts to its initial condition.

By the above description there has been disclosed a novel sealing meansfor providing a fluid joint between assembled components of valvesadapted for high temperature-high pressure service. The sealing meansincludes the simplicity of but a preformed V-shaped ring 52 of stainlesssteel or the like forced into spreading contact against concentriccircumferential channel walls on each side of the joint to bemaintained. Follower ring 60 serves as a spacer or washer to provide asuitable bearing surface for abutting engagement with the apex 56 ofsealing ring 52 to assure proper alignment and prevent relativedisplacement thereof. With the novel design of sealing ring 52, the needfor expensive maintenance procedures is avoided to insure an efficient,fluid tight joint. Ordinary machining of the parts is sufficient.

The 30 initial angle a for the leg inclination of ring 52 has been foundto provide an optimum balance between bolting force applied at 33 andrequired sealing force exerted by the ring against the channel walls 45and 46. As the angle is significantly increased beyond 30, for example,45, the required bolting force to spreadthe ring is similarly increasedwhile the sealing force exerted against the retaining channels isproportionally decreased. On the other hand, as the angle issubstantially reduced to, for example, 15, the sealing force isincreased in comparison with the bolting force. Moreover, in the lattersituation, the radial distance through which the two ring legs can moveis likewise reduced thereby imposing a much closer degree of tolerancecontrol in the manufacture of both seal ring and retaining channels.

Since many changes could be made in the above construction and manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all mattercontained in the drawings and specification shall be interpreted asillustrative and not in a limiting sense.

The embodiments'of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. In a valve including a first component defining a tubular passage forflow of pressurized fluid, and a second component secured assembled tosaid first component coaxially of said passage forming an elongatedjoint therebetween which connects with said passage, the improvementcomprising sealing means to maintain said joint pressure tight andcomprising:

a. means defining L-shaped coplanar opposite annular channels located toeach side of said joint and extending toward each other for providing acommon base between the side walls thereof;

b. a' stiffly. resilient annular metallic sealring generally V-shaped incross section with legs angularly diverging from an apex, said seal ringbeing arranged spanning said joint toward said base with its apex ingeneral coalignment with said joint and its legs diverging toward thewalls of said opposite channels and adapted to cross sectionallyterminate therewithin;

. a follower ring generally coextensive with said seal ring and havingan angular surface relatively more shallow than said ring in uniformengagement against the apex thereof; and

(1. advance means operably engaging said follower ring at a locationremoved from the seal ring engaging surface thereof to advance saidfollower ring axially against said seal ring spreading the legs of thelatter uniformly along said base into sealing engagement with the sidewalls of said channels.

2. In a valve according to claim 1 in which said joint has an axialextent and at termination is circular in section and the seal ring ofthe improvement is V-shaped in radial section through its annulus foroverlying said joint.

3. The improvement according to claim 1 in which said seal ring isV-shaped in radial section through its annulus. I

4. The improvement according to claim 3 in which said follower ringincludes a circumferential groove in the angular surface with which itengages said seal ring.

5. The improvement according to claim 4 in which the legs of said sealring are angularly inclined radially inward and outward the ring axis.

6. The improvement according to claim 4 in which said advance meansincludes bolts threaded into one of said components and means includesbolts threaded into one of said components and means moved by tighteningof said bolts and engaging against said follower ring on a surfacethereof opposite the surface in which said circumferential groove iscontained.

7. Apparatus for sealing an annular joint in a pressure fluid containerhaving a channel formed of a base intermediate substantiallyperpendicular side walls extending about said joint in fluidcommunication therewith comprising in combination:

a. a stiffly resilient annular metallic seal ring generally V-shaped incross section with legs angularly diverging from an apex, said seal ringbeing adapted for receipt within said channel spanning the joint thereatwith its apex in general coalignment therewith and its legs crosssectionally terminating against the channel base diverging toward andwithin the opposite side walls thereof; and t a follower ring generallycoextensive with said seal ring and having an angular surface relativelymore shallow than said seal ring in unifonn engagement against the apexthereof;

. said seal ring being responsive to an axial force applied from saidfollower to spread its legs along said base into sealing engagement withthe side walls of the container channel.

8. Apparatus according to claim 7 in which said seal ring is V-shaped inradial section through its annulus.

9. Apparatus according to claim 8 in which said follower ring includes acircumferential groove in the surface with which it engages said sealring.

10. Apparatus according to claim 9 in which the legs of said seal ringare angularly inclined radially inward and outward about 30 to a planetransverse to the ring axis.

1. In a valve including a first component defining a tubular passage forflow of pressurized fluid, and a second component secured assembled tosaid first component coaxially of said passage forming an elongatedjoint therebetween which connects with said passage, the improvementcomprising sealing means to maintain said joint pressure tight andcomprising: a. means defining L-shaped coplanar opposite annularchannels located to each side of said joint and extending toward eachother for providing a common base between the side walls thereof; b. astiffly resilient annular metallic seal ring generally Vshaped in crosssection with legs angularly diverging from an apex, said seal ring beingarranged spanning said joint toward said base with its apex in generalcoalignment with said joint and its legs diverging toward the walls ofsaid opposite channels and adapted to cross sectionally terminatetherewithin; c. a follower ring generally coextensive with said sealring and having an angular surface relatively more shallow than saidring in uniform engagement against the apex thereof; and d. advancemeans operably engaging said follower ring at a location removed fromthe seal ring engaging surface thereof to advance said follower ringaxially against said seal ring spreading the legs of the latteruniformly along said base into sealing engagement with the side walls ofsaid channels.
 2. In a valve according to claim 1 in which said jointhas an axial extent and at termination is circular in section and theseal ring of the improvement is V-shaped in radial section through itsannulus for overlying said joint.
 3. The improvement according to claim1 in which said seal ring is V-shaped in radial section through itsannulus.
 4. The improvement according to claim 3 in which said followerring includes a circumferential groove in the angular surface with whichit engages said seal ring.
 5. The improvement according to claim 4 inwhich the legs of said seal ring are angularly inclined radially inwardand outward the ring axis.
 6. The improvement according to claim 4 inwhich said advance means includes bolts threaded into one of saidcomponents and means includes bolts threaded into one of said componentsand means moved by tightening of said bolts and engaging against saidfollower ring on a surface thereof opposite the surface in which saidcircumferential groove is contained.
 7. Apparatus for sealing an annularjoint in a pressure fluid container having a channel formed of a baseintermediate substantially perpendicular side walls extending about saidjoint in fluid communication therewith comprising in combination: a. astiffly resilient annular metallic seal ring generally V-shaped in crosssection with legs angularly diverging from an apex, said seal ring beingadapted for receipt within said channel spanning the joint thereat withits apex in general coalignment therewith and its legs cross sectionallyterminating against the channel base diverging toward and within theopposite sIde walls thereof; and b. a follower ring generallycoextensive with said seal ring and having an angular surface relativelymore shallow than said seal ring in uniform engagement against the apexthereof; c. said seal ring being responsive to an axial force appliedfrom said follower to spread its legs along said base into sealingengagement with the side walls of the container channel.
 8. Apparatusaccording to claim 7 in which said seal ring is V-shaped in radialsection through its annulus.
 9. Apparatus according to claim 8 in whichsaid follower ring includes a circumferential groove in the surface withwhich it engages said seal ring.
 10. Apparatus according to claim 9 inwhich the legs of said seal ring are angularly inclined radially inwardand outward about 30* to a plane transverse to the ring axis.